One of the information needed for formulating the sustainable management of mud crab is the availability of information on the population parameters and its exploitation rate. The current research aimed to study the population parameters and the exploitation rate of mud crab in Sebatik Waters. Field research was conducted in March – December 2017. Samples of mud crab were obtained from the catch of fisherman by trap in Sebatik Waters. The Von Bertalanffy growth parameters were constructed through monthly modals progression analysis of the size of carapace width frequencies distributions and the exploitation rate was estimated through the method of length converted catch curve. The results showed that the carapace width of mud crabs caught by trap in Sebatik Waters ranged between 84 to 144 mmCW with the mean size of 107.05±12.3 mmCW for male and 110.2±8.86 mmCW for female. The growth of weights of male crab (b=3.6) is faster than its size, while the growth of weight of female crab was slower than its size (b=2,5). The sex ratio of mud crab was unbalanced (5.5 : 1) that the proportion of male was more dominant than female. Asymptotic carapace width (CW) of mud crab was 151.2 mmCW for male and 140.5 mmCW for female. The growth rate (K) of mud crab was 0.75 year-1 for male and 0.79 year-1 for female. The exploitation status of mud crab was starting to overfishing (E=0,5-0,55) so it suggest to not increase the fishing effort of mud crab fishery in Sebatik Waters.